COPYRIGHT2004BYTHEJOURNALOFBONEANDJOINTSURGERY,INCORPORATEDAutologous Osteochondral MosaicplastySurgicalTechniqueBy Lszl Hangody, MD, PhD, DSc, Gbor K. Rthonyi, MD, Zsfia Duska, Gbor Vsrhelyi, MD, Pter Fles, MD, and Lszl Mdis, MD, PhD, DScInvestigation performed at Uzsoki Hospital, Orthopaedic and Trauma Department, Budapest, HungaryThe original scientific article in which the surgical technique was presented was published in JBJS Vol. 85-A, Suppl. 2, pp. 25-32, 2003INTRODUCTIONThe treatment of full-thickness cartilage defects of the articular sur-faces of weight-bearing joints is a frequent problem in orthopaedic practice. Previous experimental and clinical experience with autoge-nous osteochondral grafting has demonstrated that the transplanted hyaline cartilage has had a good rate of survival1-4.It seemed to us that the use of small-sized multiple cylindrical grafts would permit more tissue to be transplanted while preserving the integrity of the donor site and that the implantation of grafts in a mosaic-like fashion would allow progressive contouring of the new surface5-7.ABSTRACTBACKGROUND:The successful treatment of chon-dral and osteochondral defects of the weight-bearing surfaces is a challenge for orthopaedic sur-geons. Autologous osteochondral transplantation is one method that can be used to create hyaline or hyaline-like repair in the defect area. This paper describes the results after ten years of clinical experience with autologous osteo-chondral mosaicplasty. METHODS:Clinical scores, imaging tech-niques, arthroscopy, histological examination of biopsy samples, and cartilage stiffness measure-ments were used to evaluate the clinical outcomes and quality of the transplanted cartilage in 831 patients undergoing mosaicplasty.RESULTS:According to these investiga-tions, good-to-excellent results were achieved in 92% of the patients treated with femoral condylar implantations, 87% of those treated with tibial resur-facing, 79% of those treated with patellar and/or trochlear continuedFIG. 1Miniarthrotomy mosaicplasty. The donor-site area is reached by extending the knee.THE JOURNAL OF BONE & JOI NT SURGERY SURGI CAL TECHNI QUES MARCH2004 VOLUME86-A SUPPLEMENTNUMBER1 J BJ S. ORGSURGICAL TECHNIQUEAutologous osteochondral mosa-icplasty involves obtaining small-sized cylindrical osteochondral grafts (2.7, 3.5, 4.5, 6.5, and 8.5 mm in diameter) from the mini-mal weight-bearing periphery of the femoral condyles at the level of the patellofemoral joint and transplanting them to prepared defect sites on the weight-bearing surfaces. Combinations of differ-ent graft sizes allow a 90% to 100% defect-filling rate. Fibrocar-tilage grouting, stimulated by abrasion arthroplasty or sharp curettage at the base of the defect, is expected to complete the new surface.Autologous osteochondral mosaicplasty can be done as an open procedure, through a mini-arthrotomy (Figs. 1 and 2), or ar-throscopically. The technique of these surgical procedures is simi-lar. There are only small techni-cal differences at certain steps of each operation.ABSTRACT | continuedmosaicplasties, and 94% of those treated with talar proce-dures. Long-term donor-site dis-turbances, assessed with use of the Bandi score, showed that patients had 3% morbidity after mosaicplasty. Sixty-nine of eighty-three patients who were followed arthroscopically showed congru-ent gliding surfaces, histological evidence of the survival of the transplanted hyaline cartilage, and fibrocartilage filling of the donor sites. Complications of the surgery included four deep infec-tions and thirty-six painful post-operative hemarthroses.CONCLUSIONS:On the basis of these promising results and those of other similar studies, autologous osteochon-dral mosaicplasty appears to be an alternative for the treatment of small and medium-sized focal chondral and osteochondral de-fects of the weight-bearing sur-faces of the knee and other weight-bearing synovial joints. FIG. 2Miniarthrotomy mosaicplasty. The recipient area is reached by flexing the knee.Figs. 3-A and 3-B Illustration (Fig. 3-A) and ar-throscopic image (Fig. 3-B) showing the use of a spinal needle to determine perpendicular ac-cess to the defect.FIG. 3-AFIG. 3-BTHE JOURNAL OF BONE & JOI NT SURGERY SURGI CAL TECHNI QUES MARCH2004 VOLUME86-A SUPPLEMENTNUMBER1 J BJ S. ORGArthroscopic TechniqueCartilaginous lesions are defined only at arthroscopy. If the preoperative differential diagnosis includes such a lesion, the patient should be advised of the possibility of a mosaicplasty. The patient should be prepared for an open procedure, as the site may be inaccessible because of its location posteriorly or be-cause of an inability to flex the knee sufficiently. Gen-eral or regional anesthesia with tourniquet control is recommended for this procedure, and prophylactic antibiotics are used. The patient is positioned supine with the knee free to flex to 120. The contralateral extremity is placed in a stirrup. Portal selection is crucial to gain perpendicu-lar access to the defect site. With use of a spinal needle, perpendicular access through a working portal should be checked. Note that these apertures should be placed more medially than usual to fol-low the curvature of the femoral condyle (Figs. 3-A and 3-B). Osteochondritis dissecans of the medial femoral condyle should be accessed from the lateral side. With use of a central patellar tendon portal, good access can be gained to the medial surfaces of both the medial and lateral femoral condyles.After the defect is identified, its edges are dbrided to healthy hyaline cartilage with curettes, a knife blade, or an arthroscopic resector blade. The base of the lesion is abraded or curetted down to viable subchondral bone (Figs. 4-A and 4-B). At FIG. 4-AAbrasion arthroplasty of the osseous base of the defect and planning of the ideal filling with use of the drill-guide.FIG. 4-CArthroscopic view of the planning of the ideal filling with use of a probe.FIG. 4-BArthroscopic view of the abrasion arthroplasty. THE JOURNAL OF BONE & JOI NT SURGERY SURGI CAL TECHNI QUES MARCH2004 VOLUME86-A SUPPLEMENTNUMBER1 J BJ S. ORGthis point, a drill-guide is used to determine the number of grafts that are needed. By tapping a drill-guide down to viable sub-chondral bone, optimal filling of the defect can be projected (Fig. 4-C). With use of variable-sized plugs, the filling rate can be in-creased from 70% to 90% or even 100% (Figs. 5-A and 5-B).During an open procedure, the peripheral parts of both fem-oral condyles at the level of the patellofemoral joint can serve as donor sites. During the arthro-scopic approach, the medial border of the medial femoral condyle is recommended as a primary donor site because dis-tension pushes the patella later-ally, allowing perpendicular access to the medial femoral condyle. If necessary, the lateral border can be used as a second-ary harvest site (Fig. 6). Notch area grafts are less favorable as they have a concave hyaline surface and less elastic subchon-dral bone.A standard contralateral portal is optimal for viewing the harvest site in a perpendicu-lar axis. The knee should be ex-tended in a stepwise fashion to access the superior donor sites. The lower anatomical limit of CRITICAL CONCEPTSINDICATIONS: Focal chondral and osteochon-dral defects of weight-bearing ar-ticular surfaces of the knee Defects of other diarthrodial surfaces of the talus, humeral capitulum, and femoral head Age of less than fifty years Diameter of defect ideally be-tween 1 and 4 cm2 Concurrent treatment of insta-bility, malalignment, and menis-cal and ligament tears essential Patient compliance (i.e., com-pliance with weight-bearing lim-itation) critical CONTRAINDICATIONS: Absolute Tumor, infection, generalized or rheumatoid arthritis Osteoarthritis Lack of appropriate donor area Age of greater than fifty years Defect larger than 8 cm2 Defect deeper than 10 mm Noncompliant patient Relative Age of between forty and fifty years Defect between 4 and 8 cm2 Mild osteoarthritic changes continuedFIG. 5-BFIG. 5-AIllustration (Fig. 5-A) and intraoperative images (Fig. 5-B) showing 80%, 90%, and 100% filling of a defect.THE JOURNAL OF BONE & JOI NT SURGERY SURGI CAL TECHNI QUES MARCH2004 VOLUME86-A SUPPLEMENTNUMBER1 J BJ S. ORGgraft harvest is the sulcus termi-nalis (i.e., the top of the inter-condylar notch). A properly sized tubular chisel is introduced perpendicu-lar to the donor site (Fig. 6). This harvester device is then tapped into the donor site. A depth of 15 mm is usually recommended for resurfacing of cartilage defects and a depth of 25 mm is appro-priate for osteochondral defects because, in the latter case, the grafts should fill the bone loss as FIG. 6The graft is harvested by toggling the harvesting chisel. The recommended donor-site locations are shaded.FIG. 7A, Illustration showing the chisel in situ with the graft inside. The chisel is toggled, with-out rotation, to free the graft. B, The graft is then removed from the harvesting chisel.CRITICAL CONCEPTS | continuedPITFALLS: Perpendicular graft harvest and implantation is essential to achieve an even surface on the host area. Nonperpendicular harvest and insertion may re-sult in step-offs on the surface. Close monitoring with use of the arthroscope and varied viewing angles helps to avoid such problems. Graft sinkage below the host surface should be avoided. Regular use of the delivery tamp can help to avoid inser-tion of the grafts too deeply. If the graft has been inserted too deeply, the following steps are recommended. First, insert the drill-guide next to the too-deeply implanted graft. Sec-ond, drill an appropriate recipi-ent hole. Third, remove the guide and use the arthroscopic probe to elevate the previously implanted graft to the proper level through the recipient hole adjacent to the implanted graft (Fig. 15). As soon as the ap-propriate graft level has been achieved, continue the recom-mended sequence for the fur-ther insertions. The larger the defect, the higher the rate of donor-site morbidity and the greater the difficulty of forming a congruent surface. Harvesting grafts for a surface defect in another joint requires the opening of an otherwise healthy knee joint. Early weight-bearing can cause the grafts to sink. Therefore, proper patient selection, regu-lar follow-up, and well-trained therapists help the patient to adhere to the postoperative protocol.THE JOURNAL OF BONE & JOI NT SURGERY SURGI CAL TECHNI QUES MARCH2004 VOLUME86-A SUPPLEMENTNUMBER1 J BJ S. ORGwell. After tapping and then toggling with no rotation, the chisel is removed and the graft is delivered from the harvester with use of a chisel guard (Fig. 7). It is very important to push out the graft from the osseous end to avoid damaging the hya-line cartilage cap. Insertion of the grafts is done through the universal guide. As a first step in the im-plantation, this guide is tapped into the osseous base of the de-fect. The 3-mm-long cutting edge is introduced into the osseous base with use of the shoulder of this device to help to define a perpendicular access to that part of the defect. With the assistance of this universal guide, a recipient tunnel is cre-ated with an appropriately sized drill-bit (Figs. 8 [top] and 9). A dilator is then used to create a conical-shaped recipient tunnel for easy insertion of the trans-planted graft (Figs. 8 [middle] and 10). Finally, insertion of the graft is done with an adjustable plunger to match the surface of the graft to the surrounding ar-ticular surface (Figs. 8 [bottom] FIG. 8Illustration showing drilling of the recipi-ent tunnel (top), dilation of the recipient tunnel (middle), and insertion of the graft (bottom).FIG. 11A and B, Arthroscopic images demonstrating the delivery of the graft.FIG. 10Intraoperative (A) and arthroscopic (B) images demonstrating the dilation of the recipient tunnel.Intraoperative (A) and arthroscopic (B) images demonstrating the drilling of the recipient tunnel.FIG. 9THE JOURNAL OF BONE & JOI NT SURGERY SURGI CAL TECHNI QUES MARCH2004 VOLUME86-A SUPPLEMENTNUMBER1 J BJ S. ORGand 11). With use of this step-by-step sequence (drilling, dilat-ing, and delivering), all of the grafts are inserted. Step-by-step implantation ensures a safe press-fit fixation. In unconfined or marginal lesions, the grafts are implanted in a perpendicular fashion. When all of the holes are filled, the knee is put through a range of motion with varus and valgus stress to seat the grafts fully and to ensure their press-fit stability (Fig. 12). The portals are closed, and the joint is drained through a superior portal. After surgery, an elastic bandage is used to diminish bleeding from the do-nor sites.Open MosaicplastyWhenever arthroscopy is not practical, a miniarthrotomy through a medial or an antero-lateral sagittal or oblique inci-sion can be used. An extended approach is sometimes neces-sary for tibial or patellotroch-lear defects (Fig. 13). The steps of the procedure are identical to those of the arthroscopic method. Mosaicplasty outside of the knee requires arthroscopic graft harvest from the knee and open access to the affected bone (talus, femoral head, humeral head, or capitulum) (Fig. 14).Postoperative Management Postoperatively, the drain should be removed at twenty-four hours. Appropriate pain control as well as the use of nonsteroidal anti-inflammatory drugs can lessen the patients complaints. Post-FIG. 12The knee is flexed and extended in a functional test of the resurfaced area.FIG. 13Intraoperative photograph, made during open mosaicplasty on the femoral trochlea, demonstrating an extended approach. THE JOURNAL OF BONE & JOI NT SURGERY SURGI CAL TECHNI QUES MARCH2004 VOLUME86-A SUPPLEMENTNUMBER1 J BJ S. ORGoperative prophylaxis against thrombosis is recommended. Postoperative rehabilitation, in general terms, starts with immediate unrestricted passive motion with non-weight-bearing for two to three weeks followed by partial weight-bearing for two to three weeks. Lszl Hangody, MD, PhD, DScGbor K. Rthonyi, MDZsfia DuskaGbor Vsrhelyi, MDPter Fles, MDLszl Mdis, MD, PhD, DScUzsoki Hospital, Orthopaedic and Trauma Depart-ment, Mexiki Street 62, 1145 Budapest, Hun-gary. E-mail address: hangody@axelero.huIn support of their research or preparation of this manuscript, one or more of the authors received grants or outside funding from the Hungarian Health Ministry. In addition, one or more of the authors received payments or other benefits or a commitment or agreement to pro-vide such benefits from a commercial entity (roy-alty payment after mosaicplasty instrumentation, Smith and Nephew Endoscopy, Inc., Andover, Massachusetts). No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, educational institution, or other charitable or nonprofit organization with which the authors are affili-ated or associated.The line drawings in this article are the work of Daniel Mller of Haderer & Mller (art@ilustracao-biomedica.com).REFERENCES1. Campanacci M, Cervellati C, Donati U. Autogenous patella as replacement for a resected femoral or tibial condyle. A report of 19 cases. J Bone Joint Surg Br. 1985;67:557-63. 2. Fabbricciani C, Schiavone Panni A, Delcogliano A, et al. Osteochondral au-tograft in the treatment of osteochondritis dissecans of the knee. In: American Ortho-paedic Society for Sports Medicine Annual Meeting, Orlando, Florida; 1994. p 78-9. 3. Outerbridge HK, Outerbridge AR, Outer-bridge RE. The use of a lateral patellar au-tologous graft for the repair of a large osteochondral defect in the knee. J Bone Joint Surg Am. 1995;77:65-72.4. Yamashita F, Sakakida K, Suzu F, Takai S. The transplantation of an auto-geneic os-teochondral fragment for osteochondritis dissecans of the knee. Clin Orthop. 1985;201:43-50.5. Hangody L, Karpati Z. [New possibilities in the management of severe circum-scribed cartilage damage in the knee]. Magy Traumatol Ortop Kezseb Plasztikai Seb. 1994;37:237-43. Hungarian.6. Hangody L, Kish G, Krpti Z, Udvarhelyi I, Szigeti I, Bely M. Autogenous osteo-chondral graft technique for replacing knee cartilage defects in dogs. Orthopedics. 1997;5:175-81. 7. Hangody L, Feczk P, Bartha L, Bod G, Kish G. Mosaicplasty for the treatment of articular defects of the knee and ankle. Clin Orthop. 2001;391 (Suppl):S328-36. FIG. 14Intraoperative photograph made during open mosaicplasty of the femoral head. The har-vest site was the ipsilateral knee. FIG. 15Elevation of a too-deeply implanted graft.